Abstract: An apparatus is disclosed for melting asphalt and for maintaining it in a molten condition without producing by-products harmful to the atmosphere. The asphalt is heated and maintained in a liquid state in an enclosed vessel by transferring heat from a heating means through inner wall portions of the vessel. Air polluting by-products are minimized due to the increased surface area heating the asphalt and the resulting reduced thermal gradient which prevents decomposition of the asphalt. A control system for selectively controlling the heating of the asphalt in a manner which reduces the production of air polluting products is also disclosed.